EP2825778A1

EP2825778A1 - Device together with hydraulic system for actuating at least one first hydraulic consumer and at least one second hydraulic consumer

Info

Publication number: EP2825778A1
Application number: EP13709777.0A
Authority: EP
Inventors: Philipp Hilzendegen
Original assignee: Hydac Fluidtechnik GmbH
Current assignee: Hydac Fluidtechnik GmbH
Priority date: 2012-03-14
Filing date: 2013-03-13
Publication date: 2015-01-21
Anticipated expiration: 2033-03-13
Also published as: US9631643B2; US20150007714A1; WO2013135375A1; EP2825778B1; DE102012005253A1

Abstract

Device together with hydraulic system for actuating at least one first hydraulic consumer and at least one second hydraulic consumer. A device (32) for actuating at least one first hydraulic consumer (10) and at least one second hydraulic consumer (12), wherein the hydraulic consumers (10, 12) can be supplied with fluid at a predefinable pressure at least via a flow divider (26) for dividing a fluid flow which comes from a pressure supply (P) into predefinable part flows which lead to the respective hydraulic consumer (10, 12), is characterized in that a fluid flow from that hydraulic consumer (10) with higher pressure loading via the flow divider (26) to that hydraulic consumer (12) with lower pressure loading can be suppressed by means of at least one shut-off device (38) which is arranged between the flow divider (26) and at least one hydraulic consumer (12), and in that the at least one shut-off device (38) is arranged in a fluidic connection (F2) from the flow divider (26) to the hydraulic consumer (12) with lower pressure loading.

Description

Device and hydraulic system for controlling at least a first hydraulic consumer and at least one second hydraulic consumer

The invention relates to a device for controlling at least one first hydraulic consumer and at least one second hydraulic consumer according to the feature configuration of the preamble of patent claim 1. The invention further relates to a hydraulic system with such a device for controlling two hydraulic consumers.

Such a device is used, for example, in machines, such as loaders, for moving loads and serves to control actuators with working cylinders, in which pistons are moved or moved in accordance with a movement of the load to be moved. Depending on the positions of the pistons or actuators and the load moved by them, tilting of the machine may occur in the event of unfavorable center of gravity displacement, which is why it must comply in particular with the safety regulations specified in the safety standard EN 15000. Accordingly, at the risk of tipping a Lastmomentvergrößernde movement to prevent and allow a load torque-reducing movement. During operation of the machine, in the event of a sudden switch-off of the loads, in particular due to a strong braking acceleration, the machine may also tilt. This problem has hitherto been counteracted by the permissible reduction of the braking acceleration is reduced, expediently the traversing speed is delayed in proportion to the actuator position and the load, in other words, the movement is slowed down. This contradicts the user-side requirement of fast loading and unloading cycles. Alternatively, the movements of both actuators may be positively coupled such that undesired actuator positions are avoided.

Furthermore, it is desirable to allow uniform, "jerk-free" working at the limits of the range of motion of the machine, in other words, when reaching the extreme positions of the actuators one associated with a horizontal movement, acted upon with a higher pressure actuator actuator to a vertical movement associated, acted upon by a lower pressure actuator fluid flow leakage flow and the position of the other actuator in the form of an irregular motion sequence, such as a "jerk", can noticeably influence. This situation occurs in particular when the horizontally movable actuator is retracted far and the vertically displaceable actuator is extended far. The known devices for controlling hydraulic consumers, such as the actuators, do not reliably prevent the fluid leakage current in this situation. By the US 5,473,828 A, a device for controlling at least two hydraulic consumers is known, each formed as a hydraulic cylinder, different extent of cylinder housings extendable piston rod drives for the purpose of driving two equally trained blade halves of an excavator. Due to the different travel lengths of the piston rod drives, it is possible to lift the blade when the blade mechanism is closed and penetrating into an earth mass break out of the rest of the ground, the closed bucket is tilted by the longer working cylinder performs the pertinent tilting movement. In order to hold the blade halves in the closed position in this tilting or Ausbrechbewegung, a control line is provided downstream of the Stromteilerpfad that supplies the working cylinder with the lower extension length, after a flow divider that supplies the two sides of the piston with hydraulic fluid a 3/2-way valve controls such that with increasing pressure when breaking the soil of this valve reaches its closed position, so that a further influx of working fluid is suppressed to this hydraulic cylinder and this is held without overload in its shovel closing position.

DE 1 1 2005 001 879 T5 discloses a fluid pressure actuator control system for controlling an adjustment of a predetermined fluid pressure actuator of at least two fluid pressure actuators as hydraulic consumers to which flows of pressurized fluid discharged from a common fluid pressure source are individually via a flow divider can be assigned. In the context of this individual allocation, each hydraulic consumer is assigned an independent blocking device which can be actuated by a central control device, wherein operating states at the respective hydraulic consumers are monitored via comprehensive sensor technology and cause the control device to be in the form of valves via the respective blocking device Supply quantities of fluid to the consumers or, preferably again, to discharge them into a tank. Because of this separate control concerning the respective hydraulic consumer, it is possible with this known solution, on the one hand a fine adjustment or fine positioning for the hydraulic consumers, for example in the form of hydraulic actuators, and further the possibility is created, the position or position of a work tool, for example in the form of an excavator bucket automatically according to the position of a respective other movable element, for example in the form of a hydraulically actuated load lifting arm adapt. The solution known to that effect is structurally complex and reliable control of fluid leakage flows in the frame mentioned above is not possible with this known solution. Based on this prior art, the invention provides the task to prevent a fluid leakage flow between two powered by a flow divider with fluid, acted upon by different pressures hydraulic consumers in a simple and reliable manner. This object is achieved by a device having the features of claim 1 in its entirety and with a hydraulic system according to the feature configuration of claim 4. An inventive device and a hydraulic system comprising such a device is characterized in that a control line from that of the hydraulic Consumers, each with higher pressure to the flow divider leading fluid connection is guided to the locking device such that the higher pressure actuates the locking device in the direction of its blocking position, so that in any pressure situation of the driven hydraulic consumers in the fluid connection from the hydraulic consumer with higher pressure fluid pressure applied to the flow divider does not reach the hydraulic consumer with lower pressurization and consequently does not actuate it in an unintentional manner. A fluid pressure present in the corresponding fluid connection maximally reaches the blocking device, which blocks a further fluid path to the respective other hydraulic consumer.

Advantageously, during operation of the device, the at least one, preferably designed as a valve, particularly preferably as a check valve, designed locking device driven by the flow divider fluid pressure and blocked by the originating from the hydraulic consumer with each higher pressurization fluid pressure. In this advantageous embodiment of the invention, it is ensured that the at least one blocking device is blocked on the occurrence of a fluid leakage current at the flow divider. In an embodiment of the locking device as a lockable non-return valve, this can be advantageously closed by the control line, wherein the line for controlling the locking device is connected in an advantageous manner fluid leading to the fluid connection from the hydraulic consumer with higher pressure to the flow divider. It is further conceivable that fluid pressures occur in both fluid directions between the interconnected via the flow divider hydraulic consumers, which are alternately acted upon with higher and lower pressure. Here are expediently two, the respective fluid direction associated, provided in the fluid connection from the flow divider to the respective hydraulic consumer with lower pressurization locking devices are provided. However, it is also conceivable according to the invention to form a blocking device which inhibits both fluid directions and corresponding fluid flows. With the aid of the device according to the invention, it is also possible, in special positions of the hydraulic consumers, to work without interference from fluid flows without interference ("jerk-free") and safely, with the solution according to the invention solution can also be realized particularly cost-effective. Former possibly via the flow divider leading leakage currents are thus avoided with certainty. In order to realize these aforementioned advantageous solutions, it can be further provided in a preferred manner that the control line between a junction of the locking device for locking the same and a branch point extends, opens in both a coming from the output of a current divider path of the flow divider fluid line and the Another fluid line that leads in the direction of the consumer with the higher pressurization or fluidfüh- rend connected to this consumer.

The invention further relates to a hydraulic system comprising at least a first hydraulic consumer and at least one second hydraulic consumer and a device according to the invention for controlling the hydraulic consumers. The device according to the invention can be manufactured as a tradable unit, independent of the hydraulic consumers and a pressure supply, distributed and used in a hydraulic system.

For use of the hydraulic system in a machine for moving loads, the first and / or the second hydraulic load can be fluid-actuated actuators, each with two separate actuator sides, which can be alternately fluid-conductively connected to the pressure supply for movement of the respective actuator. According to the pressurization of the respective actuator side, the actuator and the load connected thereto are moved. Preferably, the actuators each comprise a piston which can be moved in and out in a working cylinder, wherein the actuator sides assigned to a retracting movement of the respective piston expediently correspond to the current Dividers are connected. However, alternatively, an extending movement of the respective piston associated actuator sides may be connected to the flow divider. In this way, a synchronization, in other words a coordinated movement, both pistons and actuators guaranteed, either in the respective retraction direction or in the respective extension direction. Also combinations of coupled retraction and extension movements are conceivable.

In a further preferred embodiment of the hydraulic system according to the invention, one of the actuators comprises a telescopic cylinder with a piston preferably retractable and extendable in a horizontal direction and a further actuator comprising a lifting cylinder with a further piston which can be retracted and retracted therein in a vertical direction Locking device between the flow divider and the lifting cylinder is arranged. Here, the total movement caused by the actuators is divided into a preferably horizontally directed component of movement and another preferably directed in the vertical direction of movement component and correspondingly changeable via the telescopic cylinder or the lifting cylinder. By the inventive arrangement of the locking device between the flow divider and the lifting cylinder and a blocking of the corresponding fluid connection is prevented during operation of the hydraulic system that at a designed example for 150 l / min flow divider and a pressure of 1 50 bar in the telescopic cylinder fluid Leakage current of about 5 l / min reaches the lift cylinder.

Further advantages and features of the invention will become apparent from the figures and the following description of the drawing. According to the invention, the above-mentioned and the further mentioned features can be realized individually or in any desired combinations with one another be. The features shown in the figures are purely schematic and not to scale. It shows:

1 to 3 each show a circuit diagram of a device according to the invention with a device for controlling hydraulic consumers equipped hydraulic system.

A hydraulic system respectively shown in FIGS. 1 to 3 comprises a first hydraulic consumer 10, which is designed as an actuator with a working cylinder, more precisely a telescopic cylinder, and a second hydraulic consumer 12, which also acts as an actuator with a working cylinder, more precisely a lifting cylinder is formed. In the two designed as actuators hydraulic loads 10, 12, respectively, a first piston 14 and a second piston 16 is movably guided, wherein the first piston 14 in a horizontal direction H in the corresponding working cylinder and retractable and the second piston 16 in a vertical direction V in the corresponding working cylinder and retractable.

For adjusting the position of the respective piston 14, 16 or for a corresponding actuator movement, a retraction side 18.1, 18.2 or an extension side 20.1, 20.2 of the corresponding working cylinder is fluid-connected to a pressure supply P and pressurized with fluid with a presettable pressure. Fluid is activated by means of an actuatable

Pump 30 from the pressure supply P to the retraction side 18.1, 18.2 or the extension side 20.1, 20.2 of the respective hydraulic consumer 10, 12 promoted. In a movement of the respective piston 14, 16 on the retraction side 18.1, 18.2 or the extension side 20.1, 20.2 displaced fluid can be performed via a tank connection T back into the tank or a reservoir. With the hydraulic system shown in Figs. 1 to 3 is the Superposition of a lifting movement in the vertical direction V with a translational or telescopic movement in the horizontal direction H possible.

To jewei ls desired fluid supply of the hydraulic consumers 10, 1 2 are designed as an electromagnetically actuated 4/3-Wegeventi I trained first valve 22 and designed as an operable 4/3-Wegeventi l second valve 24 is provided. The between an EI N position (left) for pressurizing the Einfahrseite 18.1 of the first hydraulic consumer 10, a NEUTRAL position (center) to complete all Fl uidanschlüsse and an OFF Stel ment (right) for pressurizing the extension side 20.1 of the first hydraulic consumer 10 switchable first valve 22 is connected directly between the pressure supply P and the first hydraulic consumer 10 consumers. The second valve 24, which between an ON position (left) for pressurizing a Einfahrseite 1 8.2 of the second hydraulic consumer 12, a NEUTRAL Stel ment (center) to conclude sämtl IER fluid connections and an OFF position (right) for pressurizing a Ausfahrseite 20.2 of the second hydraulic consumer 12 is switchable, is such switched between the pressure supply P and the two hydraulic consumers 10, 1 2, that the second valve 24 directly to the extension side 20.2 of the second hydraulic consumer 12 and both Einfahrseiten 18.1 , 18.2 of the two hydraulic consumers 10, 1 2 is connected.

To divide one of the pressure supply P via the second valve 24 to the Einfahrseiten 1 8.1, 1 8.2 of the hydraulic consumers 10, 12 guided fluid flow into corresponding partial flows, a flow divider 26 is provided. The flow divider 26 has a first throttle 28.1 and a second throttle 28.2 which supply the 100% amount of fluid flow coming from the pressure supply P into a first partial flow leading to the first hydraulic consumer 10, for example 67%, and to the second hydraulic consumer 1 2 leading, exemplary Divides 33% amount of second fluid flow. It is understood that instead of this fixed predetermined ratio between the first and second partial flow, the two throttles 28.1, 28.2 can be individually designed differently adjustable. The flow divider 26 is designed for a volume flow range of, for example, 1 50 l / min. Here, a compromise between the minimum volume flow, in which the flow divider 26 fulfills its function, and a pressure drop via a second switching valve 34.2 to find at maximum flow. At low flow rate of coming from the pressure supply P fluid flow of the flow divider 26 operates according to the two throttles 28.1, 28.2.

In a first fluid connection or fluid line F1 from the flow divider 26 to the first hydraulic consumer 10, a check valve 36 is provided, which closes at a pressure supply to the Einfahrseite 18.1 of the first hydraulic consumer 10 via the first valve 22 to a pressure drop across the first fluid connection F1 to avoid. In a second fluid connection or fluid line F2 from the flow divider 26 to the second hydraulic consumer 12, a locking device 38 is provided, which is designed as a check valve and via a fluidfüh- rend to the first fluid connection F1 connected, designed as a leakage power line control line S is lockable.

The fluid and pressure-carrying control line S (dashed line drawn) extends between a junction AS of the locking device 38 for locking the same and a branch point AB, in which both a coming from the output A1 of a current divider path ST1 of the flow divider 26 fluid line FT opens as well as the other fluid line Fl, which opens in the direction of the consumer 10 with the higher pressurization. The current divider path ST2 of the current divider 26 is connected via the output A2 of the current divider 26 to the fluid line F2 ', which further leads to an input-side connection of the blocking device 38. The Anschlussstel le AS and the consumer 12 leading fluid line or connection F2 are connected to the output side of the check valve 38, the locking member opens in the direction of said output side at queuing a corresponding fluid pressure and otherwise taking into account the differential pressure between the input and output side of the check valve 38th can also remain in a closed Stell.

The flow divider 26 and the locking device 38 are part of a device 32 for controlling the two hydraulic consumers 10, 1 2, wherein the device 32 further includes the check valve 36 and switchable Venti le 34.1, 34.2, 34.3. A first switchable valve 34.1 is arranged in the first fluid connection F1 from the flow divider 26 to the entry side 18.1 of the first hydraulic consumer 10. A second switchable valve 34.2 is arranged to bypass the flow divider 26 together with the barrier means 38 at an immediate pressurization of the pressure supply P via the second valve 24 to the retraction side 18.2 of the second hydraulic consumer 12. A third switchable valve 34. 3 is arranged in a direct return line from the extension side 20. 1 of the first hydraulic consumer 10 to the tank connection T, that is to say parallel to the first valve 22.

FIG. 2 differs from FIG. 1 in that the second valve 24 shown on the right is in the EI N position and, accordingly, the retraction sides 18.1, 18.2 of the two hydraulic consumers 10, 12 are pressurized via the flow divider 26 and the respective piston 14, 16 perform a horizontal first retraction E 1 and a vertical second retraction E2. By the flow divider 26 through the fluid connections F1, F2 to Einfahrseite 1 8.1, 18.2 of jewei time hydraulic consumer 10, 12 guided partial flows they are forcibly coupled and the pistons 14, 1 6 move according to the flow divider 26, more precisely on the throttles 28.1 , 28.2, set Tei l- currents and the predetermined on the respective retraction side 18.1, 18.2 subvolume of the respective working cylinder in a predetermined ratio to each other. When using the hydraulic system in a machine, such as a Telelader, for moving loads moves through this forced coupling of the first piston 14 and actuator in a lowering movement according to the second retraction E2 of the second piston 16 and actuator according to the first retraction E1 a. As a result, tilting of the machine is effectively avoided by an unfavorable center of gravity displacement. The fluid displaced by the movement of the pistons 14, 16 on the extension side 20.1, 20.2 of the respective hydraulic consumer 10, 12 is led back into the tank via the tank connection T.

FIG. 3 differs from FIG. 1 in that the first valve 22 shown on the left is in the ON position and, accordingly, the inlet side 18. 1 of the first hydraulic consumer 10 is pressurized and the first piston 14 is one in FIG to the right-facing retraction E1 performs. Due to the NEUTRAL position of the second valve 24 is in the second fluid connection F2 and the flow divider 26 of the prevailing on the retraction side 18.2 of the second piston 16 pressure. In the situation shown in FIG. 3, the second piston 16 is extended far out of the working cylinder of the second hydraulic consumer 12, so that a low pressure is applied to the corresponding retraction side 18.2. This low pressure is also at the power splitter side of the check valve 36 in the first fluid connection F1. The said check valve 36 is closed due to the actuator side, much higher pressure from the pressure supply P.

At the first hydraulic consumer 10 associated side of the flow divider 26 and in the corresponding portion of the first fluid connection F1 pending fluid pressure can flow through the flow divider 26 almost unhindered and would without the locking device 38, the retraction side 18.2 of the second hydraulic consumer 12 and can undesirably influence the position of the second piston 16, in particular "jerkily." The blocking device 38 prevents such undesired influence by the blocking device 38 being exposed to the fluid pressure present in the first fluid connection F1 is controlled and closed via the control line S before such fluid flow reaches the second hydraulic connection F2 leading to the second hydraulic consumer 12 via the flow divider 26. As soon as the pressure at the entry end 18.1 of the first hydraulic consumer 10 decreases and / or the switching position If the first valve 22 is changed, fluid leakage flows are reduced via the flow divider 26 and negligibly small or completely prevented at the latest at a pressure drop at the flow divider 26. As a result, the locking device 38 is unlocked again and the retraction side 18.2 of the zw eiten hydraulic consumer 12 can be pressurized again via the position shown in Fig. 2 of the second valve 24. In the embodiment of the device 32 according to the invention, it is achieved, in particular, that trouble-free working is ensured even in special situations of a hydraulic system and thus fast charging cycles are made possible.

Claims

P a n t a n s p r e c h e

Device (32) for controlling at least one first hydraulic consumer (10) and at least one second hydraulic consumer (12),

- wherein the hydraulic consumers (10, 12) at least one

Flow divider (26) for dividing a coming from a pressure supply (P) fluid flow in predetermined, the respective hydraulic consumer (10, 12) leading partial streams with fluid can be supplied with a predetermined pressure,

- By means of at least one between the flow divider (26) and at least one hydraulic consumer (12) arranged, controllable locking device (38), a fluid flow of that hydraulic consumer (10) with higher pressurization via the flow divider (26) to that hydraulic consumer (12 ) can be prevented with lower pressure, and

- wherein the at least one blocking device (38) is arranged in a fluid connection (F2) from the flow divider (26) to the hydraulic consumer (12) with lower pressure loading,

- Characterized in that a control line (S) of the hydraulic consumer (10) with each higher pressurization to the flow divider (26) leading fluid connection (F1) to the locking device (38) is guided such that the higher pressurization of the locking device (38 ) in the direction of its blocking position, so that in any pressure situation of the controlled hydraulic consumers (10,12) in the fluid connection (F1) from the hydraulic consumer (10) with higher pressure to the flow divider (26) pending fluid pressure the hydraulic consumer (12 ) is not reached with lower pressurization and consequently not operated in an unintentional manner. Apparatus according to claim 1, characterized in that in the operation thereof, the at least one, preferably as a valve, particularly preferably as a check valve trained blocking device (38) driven by the flow divider (26) fluid pressure and driven by the hydraulic consumer (10) each higher pressurization fluid pressure can be blocked.

Apparatus according to claim 1 or 2, characterized in that the control line (S) between a connection Stel le (AS) of the locking device (38) for blocking the same and a Abzweigstel le (AB) extends, in which both a from the output (A1) a Stromtei lerpfades (ST1) of Stromtei coupler (26) coming fluid line (FT) opens as well as the other fluid line (F1), which leads in the direction of the consumer (10) with the higher pressure.

Hydraulic system comprising at least one first hydraulic consumer (10) and at least one second hydraulic consumer (1 2) and a device (32) according to one of the preceding claims for controlling the hydraulic consumers (10, 1 2).

Hydraulic system according to claim 4, characterized in that the first (10) and / or the second hydraulic consumer (1 2) is a fluid-actuated actuator with jewei ls two separate actuator sides (1 8.1, 20.1, 18.2, 20.2), for a movement (E1, E2) of a respective piston (14, 16) can alternately be conducted in fluid communication with the pressure supply (P). Hydraulic system according to claim 5, characterized in that the pistons (14, 16) are each guided in and retractable in a working cylinder, and in that the movement of a retracting movement (E 1, E2) of the respective piston (14, 16) associated actuator sides (18.1, 18.2) are connected to the flow divider (26).

7. Hydraulic system according to claim 5 or 6, characterized in that one of the pistons (14) in a telescopic cylinder, preferably in a horizontal direction (H), is guided and retractable that another piston (16) in a lifting cylinder, preferably in a vertical direction (V), is guided in and extendable, and that the locking device (38) between the flow divider (26) and the lifting cylinder is arranged.